Dark Soul
by Sammiekinz09
Summary: When Marshall was young he lived a happy life,till tragedy hit him. As he made a deal with the devil Horns of black protruding from the sides of his head & a matching tail,sharper at the tip than any blade. Black tendrils oozing from his mouth as it devoured him and making him as pale as the moon itself.He was the Demon of Trickery and Desire.His target was Fionna. (lemons later)
1. Porloug

Thank you everyone who have Reviewed, Followed, Favorited or even read my stories. I am truly happy how people are beginning to take a liking to my FIonna and Marshall lee first story. and I'm happy to say that my first Fionna and Marshall lee fan fic was a great start and I will be still working on it. And I will be finishing the next chapter of Vulnerable for you guys and I thought I'd update this new story for you to keep you guys busy till then. Ha ha :3 This one is going to be semi OOC for the Marshall and FIonna. And its going to be a little bit darker then my other one. Once again thank you everyone for all your support without you guys I wouldn't be able to continue with the stories! :D

So here is your new story of Fioona and Marshall lee3

=XXX=

It is sad to say...not every story will have a Happy Ending.

.

.

.

Each step she takes is somewhere she doesn't know.

.

.

.

Each moment he waits for her in the shadows Watching her like prey

.

.

.

She will dance in the night, with the spirits calling her name;

.

.

.

As the Prince Of the night will fight off the Hell she will have to pay.

**D**ark **S**ou**l**

Prologue

The Demon of Trickery and Desire, The Vampire King.

It was the coldest of December nights in the small quiet town. A light snowfall outside the window of the nursery. Where a young Demon woman was giving birth to her first child. There were screams of pain followed by cries of pure joy as the doctor exclaimed, "It's a boy!" The cheerful father smiled triumphantly. No sound was heard from the child until a small pat on the butt gave way to a series of pitiful cries of the infant.

The gift of life was a magical one as the family crowded the mother's bed to get a peek at the small bundled up child as his soft fuzz black new born hair could be easily seen. The innocent dark coal hues gazing around in curiosity as the child was passed from hands to hands.

An innocence that wouldn't last forever. As the candles were blown out and the child fast asleep in the wooden crib, the house fell silent. That was the first night to start a future that couldn't be avoided. The child was born with a birthmark the shape of a small crown. He had been marked for the dark being beyond death a curse from, Lucifer himself.

As the young boy grew, his parents taught him of manners and kindness. To treat everything as precious as the wings of a butterfly. One wrong move and you could sentence the innocent creature to a slow death. The bright black haired child was well known in the town, always doing his best to help the elderly and use his manners. He wasn't born into a wealthy family, they had many struggles and when his mother fell ill he kept to her side.

Tending to her every need while his father worked in the of the underworld factory, to make ends meat with the pilling bills. No boy so young should have to take care of his mother as she laid dying. Having to watch the life slowly drain from her, taking her rosy cheeks away and leaving nothing but a pale empty carcass as she passed on a November evening. There he was, in black staring at the wooden coffin that held, what used to be his mother, a now hollow corpse. The tears urged but wouldn't come as he watched the men relay the dirt and walk away. For hours he stood, holding a single white lily in his small hands. After some time he set the flower on the freshly packed ground and wept for the loss of his mother.

For years after his dear mothers death, he wasn't the same boy. His voice had softened to a deep smooth velvet tone, and his eyes had dulled. Marshall was no longer there, just a distraught young man with no mother and only the factories to look forward to as he turned 16. "It's time to become a man and start earning your living son," his father spout at him. With a lifeless look he watched and listened. A few years later when he was about 19 his father was in a terrible accident, As a piece of machinery completely severed his arm from his body.

He lived for about 3 days before passing in bed as his mother had before him. As death was a cruel curse, This time he felt no sadness, just darkness overtaking his once pure soul. He wanted revenge for the cruel god of death that had taken his parents from him. To rip the wings off of butterflies and watch them squirm and die a slow painful death. There was no innocence left. If only he had known what would happen on his 21st birthday. The terrifying truth that was hidden away from him.

After taking all his family owned belongings and selling it, As he moved from the underworld to the realm of the humans to France, finding a life as a socialite. His inviting eyes and sexy grin, making him quite a hit with the ladies. His black hair had grown to his shoulders and he kept in pulled into a loose ponytail, as most men in the 1800's. With new women every night and all the alcohol he dared consume it was a seemingly perfect life for the orphan, until December 10th.

His eyes shot open as he sat up to look around the cold dark room. "Is anyone there?" he asked, calling out into the darkness as he tried to light the oil lamp. Suddenly, the flame appeared itself as well as a man in a dark feathery cloak and fiery red hair, his eyes equally as red. For a moment Marshall lee stared in awe before speaking. "Who are you? How did you get in here?" The figure only chuckled and waved a hand. "In due time child… I've come to make a deal."

At first the thought to stand and threaten the male came to mind before being replaced with a smile. "A deal? I'll hear it." Marshall lee had become quite the gambler and loved to make deals and bets. "Alright Marshall lee, I've come to make you an even more powerful demon. With powers to take the souls of others as god had done to you." He offered. "H-how do you know my name?" Marshall spooked surprised "That isn't important. I'm Lucifer. I know more than you can imagine." The devil himself wanted him to be an all more powerful demon?

"What's the catch?" Lucifer laughed and nodded. "Clever boy. You will have to do as I say for eternity and live among the humans, trapped between time." Eternal life and power didn't seem like much of a catch, but boy was he wrong as he held out his hand. "Deal."

With that the light blew out and only a demonic eerie laugh was heard as Lucifer would appear behind the young ,male and sank his sharp fangs into his neck. Spreading the poison threw his vains. Making the deal and had made Marshall a demon. His black hair glowing a dark black more sinister then its natural dark color. His black hues turning red, but not affecting his vision.

Horns of black protruding from the sides of his head and a matching tail, sharper at the tip than any blade. Black tendrils oozing from his mouth as it devoured him and making him as pale as the gray moon itself. Thus Marshall was born, the Demon of Trickery and Desire. A most deadly combination.

"mhm there is something else I should tell you…You will need to feed of the crimson blood of others You are now The Vampire King…My son…" Lucifer smirked darkly as he disappeared into the shadows.


	2. Chapter 1

Thank you so much to everybody who reviewed the prologue. I've never written an AU Adventure Time before. so I was a bit apprehensive about posting the idea to begin with. I'm really glad that many readers seem to have taken interest in this, and hope that you'll all continue reading and enjoying the plot. As mentioned in my profile, this will be a dark, somewhat morbid tale in places with explicit descriptions/themes of an adult nature, And supernatural .You have been warned people. Please review and like if you want more chapters. And to let you know the characters are human in this one for example LSP(lumpy space princess) turtle princess, and hotdog prince ect ect are not there usual animal or alien form they are in human form.

Thank you

=XXX=

When by Fate's design his eyes fell upon her

.

.

.

Her unique beauty incomparable

.

.

.

A maiden of light

.

.

.

Precious, beloved

.

.

.

A protective sister of life

.

.

.

From Heavens above, an angel of earth.

=XXX=

**D**ark **S**ou**l**

**Chapter one**

Fionna had been dreaming of a vast, flourishing vacant meadow scattered with many different carnations, daisy's, and lillys of every hue beneath the sun in their fully bloom beauty. In her hand had been a single stem from the red variety of carnations – which she'd supposed had to mean something important given the context of the place and very detailed of the flower itself – when the pleasant sequence of her pleasant dream had been rudely interrupted by an incessant, echoing ring that would keep going, as if it was getting louder with each new ring to just annoy her. It had been easy to ignore at first, until it swiftly exploded into a riotous din. The shrill, intrusive sound was adamant that it would tear her from the warmth, blissful embrace of her sweet slumber.

Fionna groaned and lifted her left arm – why did it feel so damned heavy? - and lashed blindly out at the source of the noise. A loud clatter informed her that she had successfully knocked the orange cat-shaped alarm-clock from its pedestal home a top her wooden bed-side table. Good, she thought, feeling strangely satisfied with her first accomplishment of the day.

It would survive, for it was a sturdy contraption that had seen many worse a fall from either higher or harder falls. As she was just about to roll over and somehow try to remember and connect the dots of her dream, when her mobile phone, inspired by the clock, began to ring in a familiar turn that she picked for her friends ringtone.

Cake…she thought as much

"What Cake?" she grumbled in greeting her loud curvyius sister.

"What? "Cake's voice shrieked at the other end of the line, so loud that a wincing Fionna had to physically remove the phone from her poor ear for a moment. "What do you mean what Baby GIRL? I'm out the door. I'm stopping to get us a skinny coffee along the way so don't bother stuffing your face at home, okay? You'd better be up! I don't want us to be late got it?"

"mhm…okay…okay I'm getting up" She yawned as she waited for her sister to respond.

"good girl, remember we have to make it at the airport for the University trip." Cake stated as she was getting the coffee for them both. "I will see you in a few, I packed up the suite cases into the car so don't worry about that okie hunbun love you" with that the line went dead.

Fionna walked down the wooden steps from the second floor, where the bedrooms resided, to the first floor living area and kitchen.

The aroma of baked goods invaded her nose and was seducing her mind to take her to the designated area. The kitchen was always her favorite to hide, the nice smells and the polite quite atmosphere always made her feel safe and good; no matter what would go wrong in her day, whatever caused her to be in a grumpy mood of anything at all, the kitchen was always the first place to go for Fionna mostly for one reason only...

A voice lightly startled the blonde haired older teenager as she stepped into the warm kitchen. "Fionna, my little girl! You're up on time, aren't you?"

Bright blue irises saw the short, plump elder man smile up to her with a wrinkling tease. His aged teeth glinted when he raised his palm to Fionna's cheek. Ice King was her adopted grandfather. Silver/white hair and dark eyes, wrinkled like a raisin in the sun with a pale blue icy skin tone, Wasn't the typical grandfather.

Ice Kings personality was like a hyperactive child on a sugar rush, yet sometimes his bones would remind him that he is...a little too old to do cartwheels. Fionna always enjoyed her Grandfather's energy and how it would always brighten the mood in any given day. As to how he got that nickname ice king was to the fact he loved winter snow and ice. As he would make beautiful ice figures and other beautiful things made of ice that no one could measure to his work.

"Good morning, Grandpa Ice king" She spoke to him in a soft angelic voice.

He would pat the blond locks that reached FIonna's waist, her hair has grown ever since she was a young child. Ice King was actually the one who suggested for her to grow her hair long. He would give her a toothy grin as he noticed she hasn't changed out of her usual blue and purple pj's.

"shouldn't you be getting ready? Your sister will be back soon Fionna haha" Ice King laughed a little a mused by his granddaughter.

"I know geeze ha ha, I couldn't help but smell your yummy cinnamon bums I wanted to take one for the trip." She would laugh as she rubbed the back of her head.

"well, they are here for you guys, I made this morning. But if you want them you're going to have to get read and no buts about it got it missy" Ice king would cross his arms eyeing his young granddaughter. Fionna would stare back for a few moments as she would sigh giving in to her grandfather. As she would make her way back up the stairs to her room once again, as she would open her closet she would grab a pair of dark blue fitted jeans and light blue quarter sleeve shirt that had two swords crossing each other on the front. She would grab tall brown boots over her white socks. As she would finish she place her favorite white bunny ear's hat on top her blond locks. As she was about to exit the room she noticed her small carry-on bag that had all her essentials, tooth-brush ,tooth-past, brush and some lotions and such for her trip with her sister.

Fionna would walked down the wooden steps from the second floor once again, as she made her way into the yummy aroma coming from the kitchen. As she saw her grandfather holding out a small bag filled with yummy mouthwatering cinnamon bums. "there now don't you feel better not that your all cleaned up…heh and here I put them in the bag for you and Cake." Her grandfather smiled half-heartedly as he saw Fionna take the small bag from him. As if right on queue Cake busted threw the front door with her hand holding one coffee in her hand as the other was sitting the porch railing.

"Come on Fionna we gotta hurry if we want to beat traffic! "Cake shouted as she ran inside to the kitchen as she would grab her younger sisters hand. As the two sister's would kiss their grandfather on the cheek good bye, leaving him for the long awaited trip. Ice King would smile tenderly as his eyes were filled with happy and sadness seeing his only grandchildren leave for their fun adventure.

Soon the girls would get into the black convertible were Cakes boyfriend monochromicorn was sitting in the drives seat waiting for them. He would smile softly at them both as Fionna would place her small carryon-bag in the trunk of the car. And make way to the back seat, as Cake sat in from passenger side next to her boyfriend. Slowly the black vehicle backed its way out of the driveway as it made its way to the street, its engine roared loadly as they drove off to the airport were their adventure awaits them.

**Authors note: **

Hey everyone here is the first chapter of Dark Soul I know this is a little short but I do plan to wright a bit more for the next chapter to come. I do hope you like this one and please remember to review or if you have any idea' please let me one :3.


End file.
